Insulating Flat Roof With Spray Foam

It s not coming from above the roof and it s not some new moisture source resulting from the spray foam.

Insulating flat roof with spray foam.

The effective roof insulation layer may range in thickness from 3 to 12 cm as needed. Lstiburek takes blame for bad language. Holladay informed west that these options were discussed in a recent gba article insulating low slope residential roofs. Add some wood blocking at the roof edge for fascia to match insulation thickness and coat the spray foam and done.

This means the insulation can be sprayed onto the underside of the flat roof to create a solid water resistant and pest resistant protection barrier. A layer of spray polyurethane foam can be installed against the underside of the roof sheathing with the rest of the rafter cavity filled with air permeable insulation. Install composite insulation made from expanded polystyrene or eps foam laminated with a fiberglass facer that meets ul class a requirements. What s left he adds are using spray foam insulation on the underside of the roof sheathing or rigid foam on top of the roof sheathing.

Spray foam insulation is in a liquid form until it comes into contact with a surface where it begins to expand from its initial size up to a hundred times. The movement of air into indirect conditioning of an unvented attic is a slow gradual process that will not be noticeable by occupants and typically will not put any strain on the hvac system. For a 1 inch board equivalent of 6 r value. Moisture generated indoors or that infiltrates into the home is responsible for the bulk of the moisture in an attic insulated with spray foam on the underside of the roof sheathing.

5 0 out of 5 stars 3. Composite insulation works in flat and low sloped. Such an insulating solution involves applying several layers of pur foam with each layer around 1 2 cm thick. We recommend having at least 20 r value worth of material for optimal energy efficiency.

00 0 40 oz free shipping. If the guy is worried about spray foam in the house then put it on the roof. Closed cell polyurethane spray foam will prove ideal for thermal insulation of a flat roof. You can expect to pay about 55 100 sq ft.

You must meet the same minimum code requirements for the spray foam layer and the total assembly as for the rigid foam plus air permeable insulation approach. 3 8 out of 5 stars 129. Foam it green 602 closed cell spray foam insulation kit. Touch n seal high density spray foam roof insulation kit 3 0 pcf closed cell foam 120 bf.

While expensive the best insulation is polyiso rigid foam.